Hi Kiran Nemade
There is one thing that comes to my mind
you need an ID attribute in each entity other than the ID generated by Mendix and a foreign key ID in the server entity to reference the application
and set these IDs on each create object activity you need a helper object that has only 2 ID attributes
In the MF where you publish the service retrieve all things and create objects of the helper entity to set the ID attributes then expose the helper entity
I hope I could simplify the scenario